diff --git a/README.md b/README.md
index 8a8f533..8a7894e 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@ A comprehensive RTLola tutorial can be found [here](https://rtlola.cispa.de/play
 - `colcon build`
 - `source install/setup.bash`
 - `ros2 run rtlola_testnode testnode`
-- start new terminal
+- start new terminal and source ROS 2 
 - `source <path_repo>/test_ws/install/setup.bash`
 - `cd <path_repo>/monitor`
 - fill out [ros2_config.toml](monitor/ros2_config.toml):